Daylight Influences Bacterial Communities

Summary

What happens to the microbial communities in a room when exposed to lots of sunlight? We decided to find out.

For our pilot study, we created “lightboxes” (Figure 1) to look at the effect of natural light on bacterial communities in dust, separate from the microbial influences of human occupants or outdoor air. The boxes are each a single room, with single window covered by filters to control the amount and type of daylight which shines on the dust inside. House dust was collected from a variety of different homes and homogenized to create a single starting sample. Aliquots of that homogenized dust were dispensed into petri dishes inside the lightboxes, which were installed on a roof at the University of Oregon to catch natural daylight.

Figure 1

Figure 1. Light Box

We found that sunlight killed bacteria in house dust, meaning that natural sunlight may have bactericidal properties on a larger scale. These findings have a lot of potential, especially in the medical and design industries. In the future of bio-informed design, letting in daylight might be the best sustainable solution for occupant health.